1. Field of the Invention
The present invention relates to a regular-interval mail feeding apparatus used in an automatic mail handling system, in which a predetermined number of fed mails are temporarily stored, and are then sent out at regular intervals.
2. Description of the Related Art
The regular-interval mail feeding apparatus of this type is disposed between two other apparatuses in the conventional automatic mail handling system. One of these apparatuses, for example, automatically discriminates the kind of mails, arranges the mails in a predetermined direction, and postmarks them. The other apparatus, for example, automatically reads mail delivery-area codes (in United States, it is called as a ZIP code) from the postmarked mails, and sorts the mail in accordance with the read codes.
Various kinds of mails, such as sealed mails and postcards, are fed in layers to an inlet of the automatic mail discriminating/postmarking apparatus. At the inlet of this apparatus, the corresponding sides of the mails are arranged so as to be substantially parallel to one another. However, the extending directions of the four sides of the individual mails, which are based on the positions of stamps and postage-fee prints thereon, are not uniform in the inlet. The mail discriminating/postmarking apparatus automatically discriminates the kind of the mails fed to its inlet, and then change the posture of the mails so that all the sides of the mails are oriented as specified. Subsequently, the apparatus conveys the oriented mails to an automatic postmarking machine for postmarking the mails.
The time for the mail fed from the inlet of the automatic mail discriminating/postmarking apparatus to reach the automatic postmarking machine depends on the kind of the mail and the posture thereof at the inlet. The reason is that the mail varies in length depending on the kind thereof, and the time required for the orientation of the mail depends on the posture of the mail at the inlet. Accordingly, the intervals at which the postmarked mails are sent out from the automatic mail discriminating/postmarking apparatus are not uniform.
Thus, the postmarked mails may be fed at irregular intervals, directly from the automatic mail discriminating/postmarking apparatus to the automatic mail sorting apparatus, without passing through the regular-interval mail feeding apparatus. In such a case, when the mails are fed at shorter intervals than the aforesaid regular intervals, the sorting apparatus in sorting operation fails to catch up with the feed, thus entailing jamming of the mails. This results in lowering of the handling capability of the whole system.
The regular-interval mail feeding apparatus, which is intended to prevent the system's handling capability from lowering in a case that mails of various kinds are fed to the inlet of the automatic mail discriminating/ postmarking apparatus, however, is subject to the following drawbacks.
If a large number of mails of a single kind are fed to the inlet in a manner such that all the sides of the individual mails are oriented as specified, the mails can be discharged at regular intervals from the automatic mail discriminating/postmarking apparatus, since they need not be discriminated in kind or reoriented. Even these postmarked mails, however, are fed to the automatic mail sorting apparatus only after being temporarily stored in the regular-interval mail feeding apparatus. In this case, the storage in the feeding apparatus has no significance, and the time for this storage lowers the handling capability of the whole aforesaid system. In this case, the temporary storage only increases the possibility of the jamming of mails.
The mails of a single kind include, for example, various mails of invitation or direct mails delivered to expected customers from companies or shops.